Delocalization in the hot deformed hypernucleus Λ21Ne

We investigate the effects of temperature on the structural evolution and clustering in the hypernucleus, taking Λ21Ne as an example, in the framework of deformed finite-temperature Skyrme–Hartree–Fock. The SkI4 Skyrme force is employed for nucleon–nucleon interaction, while the NSC97f force is used for the hyperon–nucleon interaction. It is found that the system exhibits a strongly deformed ground state with pronounced α-cluster correlations and localized density distributions at low temperatures. As temperature increases, nuclear deformation weakens, the nuclear density spreads over the surface, and clustering gradually diminishes and vanishes entirely at T≈2.8MeV. This is because that the thermal excitations lower the Fermi surface and enhance single-particle level splitting. In particular, owing to the lower excitation threshold of hyperons in the hypernuclear system, the hyperon radii exhibit a stronger temperature dependence than the nucleons. We further analyze the temperature-dependent changes in deformation, single-Λ binding energy, and entropy, providing new insights into the thermal evolution of the hypernuclear structure.